Automatic clutch



K. E. LYMAN AUTOMATIC CLUTCH Filed Au /so, 1955 Sept. 22, 1936.

2 Sheets-Sheet 1 atented Sept. 22, i36 i i AUTOMATIC crn'rcn Kenneth E.Lyman, Lake Forest, Ill.

Application August 30, 1933, Serial No. 687,433

G-Ciaims.

The present invention relates in general to clutching mechanisms forpower shafts and has particular reference to an improvement in automaticmechanisms of this character which is especially adapted for use inconnection with the power shafts of automobiles and other such machineswherein it is necessary to disconnect the drive between driving anddriven shafts.

The primary object of the invention is to provide a mechanism of theclass described which may be economically manufactured; which will bepositive and reliable in use; which will require little or no servicingoutside of adjustment to compensate for wear on the friction parts andwhich may be used in conventional types of automobile assemblies.

While the foregoing briefly explains the nature of the presentimprovements, other objects and advantages not herein specificallyreferred to will be readily appreciated upon a full comprehension of thenovel features presented in the con struction, arrangement and manner ofoperation of the clutch. I

In order that the invention may be readily understood, an embodiment ofthe same is set forth, in the accompanying drawings, and in thefollowing detailed description.

It is understood thatthose skilled in the art may make various changesin the construction and arrangement of the parts without departing fromthe spirit and scope of the invention as defined in the subjoinedclaims, and I therefore do not wish to be restricted to the preciseconstruction contained herein.

In said drawings:

Figure 1 is a view in end elevation of a mechanism embodying myinvention.

Figure 2 is a section taken on the line 11-11, Figure 1.

Figure 3 is a detailed view of a portion of the mechanism illustratingthe active position of the centrifugal operating means which renders theclutch automatic in its action.

Figure 4 is a detailed view in section on the line IV-IV, Fig. 2.

Figure 5 is a detailed view in section on the line V--V, Fig. l.

internal combustion engine or any other power source and the shaft 6will be connected to the load to be driven.

The shaft 5 is made with a flange l and terminates with a reduceddiameter 8 which projects through the center opening 9 in the side of adrum like structure I0, preferably a flywheel. The flange 11 is securedto the flywheel by means of bolts or the like ll. Provided in thereduced 5 diameter!) of the shaft 5 is an internal bore made. toaccommodate the pilot; H on the extremity of the driven shaft 6. Theinternal bore in this connection is equipped with an anti-frictionhearing, not shown, so as to allow relative rotation 10 without unduefriction of the shafts 5 and 5 when 'the clutch is disengaged.

Since the special field of utility for the inven tion is in connectionwith motor vehicles, I have elected to illustrate the same incombination with 15 a flywheel and for this reason, the self-starterteeth it are shown on the flywheel.

Axially slidable on the splined area it of the driven shaft 6 is acollar it which is made with a radial flange It to provide a support ormounting for the sheet metal plate ll of the driven clutching element.This plate ll is fixed to the flange it by means of rivets or the like[8. The plate I1 is circular in shape and is backed on one side by aring like layer of friction material i9 25 and on the other side by asimilar ring 29 which is interposed between the plate if and thepressure ring 2!. The pressure ring 2| is mounted for rotation with theflywheel ill, at least it is held against relative rotation by any meanssuit- 30 able for the purpose, preferably by headed pins or the like 22(see Fig. 5) which are set in openings 23 in the flywheel so that theheads 26, thereof, may seat in slots 25 in the periphery of the pressurering 2!. There willpreferably be three of these retaining devices andeach will be equipped with a spring device26, one end of which will bearagainst the heads 2%, the opposite ends being secured by ears 2!projecting from the face of the pressure ring. The driving connectionbetween the driving and driven clutching elements will be eifected whena thrust is imparted to the pressure ring 2i to move the same forwardlyin the direction of the driving shaft 5, When this happens, the ring offriction ma- 5 terial 19 will be moved into abutting relation with thefixed surface 28 on the flywheel so that the sheet metal plate ii isclamped to rotate with the driving shaft 5 and since it is fixed on thecollar l5 which is splined on the driven shaft, the driving and drivenshafts will thus be connected in driving relation.

The driven clutching element by means of this construction is mountedfor axial sliding movement on the splined area it of the driven shaft 6.

To shift the driven clutching element automatica1ly,I have devised acentrifugally responsive device or devices and assembled the same incombination' with a linkmotion so that when the centrifugal device ordevices move outwardly in response to the speed of the driving shaft,the link motions connected therewith will impart the desired thrust tothe pressure ring 2|. In the preferred construction I use three of thesecentrifugal devices comprising the weights 29. Each weight is pivotallymounted as at 39 in a bifurcated ear 3| and with the ears projectingfrom the inside face of a cover plate 32. The cover plate is secured tothe. flywheel ID by means of bolts or the like 33 and has preferably aplurality of stepped diameters, the smallest of which, shownat 34,comprising a collar or the like.

' concentrically mounted relatively to the driven clutching element andhoused within the flywheel is a follower plate 35. This plate isconnected to the cover plate by means of the springs 36, one

end of each spring being fixed to the projecting ears 3'! on the coverplate and the opposite ends being fixed to ears 38 on the plate 35. Theplate is spaced from the pressure-ring 2| by means of the springs 39.There are preferably three of these springs 39 and the pressure ring 2|is made with-bosses 40 providing seats for similar ends of the springs39 with the opposite ends of the springs seated in cupped depressions 4|provided in the plate 35.

The thrust or pressure imparted to the pressure ring 2| is transmittedfirst through the follower plate 35; then through the springs 39. Theplate 35 like the driven clutching element is axially shiftable andsince the pressure ring 2| is spaced from the follower plate 35 byspring devices, both the follower 35 and the pressure ring are shiftableagainst the yielding influence of the springs 26, and the springs '26together with the springs 36 automatically declutch the mechanism whenthe centrifugal force of the weights 29 is below a predeterminedminimum. In other words, when the flywheel I0 is rotated and its speedof rotation is sufiicient to throw out the weights 29 to an extentsufiicient to overcome the resistance of the springs 26 and 36, theweights will impart the necessary thrust to throw the clutch in.

now described. These link motions each preferably comprises a linkmember 42, one'end of which is pivoted as at 43 to an ear 43a projectingfrom one face of the follower 35 with the opposite end of the linkpivoted as at 44 to its respective weight 29. The relative position ofthe pivot centers 39, 43 and 44 is of importance in order to realize thedesired effectiveness of the thrust to be imparted, as well asto preventthe links from moving into a position which would carry the axis ofpivot 44 past the plane through the axes of pivots 30 and 4 3. For thisreason, the center of the pivot 44, when the clutch is out, will beordinarily in the same transverse plane as the center of the pivot 30.As the weights move outwardly about their fixed pivots 30, the linkswill move forward and the center of the pivot 44 will have a concentricmovement about the pivot 39. At the limit of the movement of the links,the relative position of the centers of the pivots 30 and 44 will besubstantially as shown in Fig. 3. In this position the clutch is engagedand the centers of both the pivots 43 and 44 are below a horizontalplane through the center of the pivot 30. In this way whenever the speedof the driving shaft decreases to an extent whereby the springs willovercome the centrifugal force of theweights, the weights may moveinwardly and there will be no danger of the weights being locked in theextended positions.

At the same time the angle of the links relative to the center of thepivots 39 will be sufficient to develop a decided thrust when the sameis required and in this connection attention is called to the fact thatthis decided positive thrust is realized with relatively small weights.To limit the movement of the linksas well as the weights,

the corner 45 of each weight is adapted to abut against a stop. Thesestops limit the throw of the weights and also the extended position ofthe links.

In addition to the automatic control I have also provided means formanually disengaging the clutch. This manual manipulation is performedpreferably by a hand or foot manipulated yoke 46 having'a pair ofdiametrically opposed trunnion pins 41 seated in an annular groove 48 inan axially shiftable collar 49. Wound around the sleeve'34 of the cover32 is a compression spring 50. The spring bears against the shoulder 5|on the cover 32 and against the collar 49, tending to retain the collar49 at' the limit of its extended position to the right, as viewed fromagainst the resistance of the spring 50 but prevented from rotation.Seated in an annular groove in the extremity of the sleeve 52 is one endof a rocker arm or finger 56, the same being pivoted as at 51 with itsopposite end presented behind a nut 58 on the threaded headless bolt 59.Any number of these actuating fingers 56 may be employed to meetrequirements. This is also true of the bolts 59.

The bolts 59 extend through openings in the cover 32 through thefollower plate 35 and seat in axial bores made to receive them in thebosses 40 on the pressure ring 2|. These shafts provide a guide for thefollower plate 35 and since they are preferably threaded or otherwisefixed to the pressure ring 2|, they are adapted to shift the pressurering axially in response to movement of the actuating fingers 56.

Manual manipulation of the collar 49 to shift the same axially will rockthe fingers 56 on their pivots 51, moving the fingers into engagementwith the nuts 58 on the bolts 59, thus exerting a backward thrust to thebolts 59and moving the pressure ring 2| into a neutral position or adeclutched position, so to speak.

This additional control is provided primarily for the purpose ofdeclutching the mechanism, should the automatic control fail to respondfor any reason. Furthermore, the manual control may be used wheneverdesired and is operable regardless of the position of theweights.

To adjust the mechanism to compensate for aooaiva direction thetension'of the springs 39 will be increased and by turning the bolts inthe opposite direction the tension will be relieved.

The pressure exerted upon the pressure ring ii is transmitted from thecentrifugally operated links 62 to the follower plate and through thesprings 39. This produces a yielding effect in the direction of thethrust which of course is desirable tolrealize a smoother and yetpositive operation of the clutch.

It should be explained further that since the springs as are compressedbetween the pressure plate fl and the follower plate 35 which platesmove as a unit, the p1ate-35 may be moved to pro- Ject the plate itagainst the driven friction element without causing furtherc'ompression'the springs 39 and hence without increasing the tensionthereof. Whether the springs 39 are further compressed depends upon theextent of their static compression between the plates. If the staticforce of the compressed springs exceeds that applied to the plate 35 bythe inertia weights 3d incident to closing the clutch, then the springsit will not be compressed nor will the tension thereof be increased. Thetension of the springs 36, however, is increased as a result of theclutch closing movement of the plates 35 and fl .and

may be relied upon to retract the plates and to move the weightsinwardly when the centrifugal force later becomes insumcient to overcomethe influence of the springs 36. Assuming that the follower plate 35 isin contact with the nuts bl by reason of spring tension in springs asand the clutch is in operating position, the manual effort necessary fora disengagement of the clutch is that force necessary to overcome thespring tension of springs 39. Also when the speed of rotation of theassembly is lnsumcient to move the weights outwardly against theresistance of springs 36, the pressure ring 2i exerts no clutchingpressure because of the bolts 59 and nuts ti whichiirnit the separationof the ring 2! from the plate 35 under the influence of the springs 39.To change the range of expansion of the springs 3d, the nuts 6i may bemoved to the right or left on the bolts to as occasion demands. Ifturned to the left, viewed from Fig. 2, the tension of the springs 39will be increased but their range of expansion limited'or decreased. Ifturned to the right, as viewed from Fig. 2, the tension will be relievedand the range of expansionincreased.

I claim as my invention:

i. in a clutch, driving and driven elements, a clutching elementcontributing to a clutching con= motion between said driving and drivenelements, a pressure member, to the rear of said shiftable clutchingelement for actuating said element, threaded bolts connected to saidpressure member, manually operable means connected with said bolts forshifting said pressure member, a follower member through which saidbolts extend with freedom of sliding movement, a yieldable connectionbetween said pressure member and.

said follower member, a plurality of centrifugal weights to the rear ofsaid follower member mounted to swing outwardly in response tocentrifugal force, and thrust imparting link motions between saidweights and said follower member.

2.1n a clutch, a driving shaft, a flywheel mounted to rotate with saiddriving shaft and having a hollow interior, a cover for inclosing saidinterior, a driven shaft extending through said cover, a clutchingelement, means for automatically shifting said clutching element, saidmeans comprising a plurality of centrifugal,

"weights on said cover, an axially movable follower member, link motionsconnecting said weights. with said follower member, a pressure memberfor actuating said clutching element, yieldable means connecting saidfollower member a with said pressure member, and means for manuallyshifting said pressure member independently of the automatic means,comprising a plurality of bolts connected with said pressure memher andslidably mounted through said follower member, a plurality of pivotedfingers connected with said bolts, an axially shiftable sleeve insurrounding relation to the driven shaft connected with said fingers andmanually operable means for manipulating said sleeve.

3. In a clutch, driving and driven elements, an axially shiftableclutching element contributing to a clutching connection between saiddriving anddriven elements, a pressure member for actuating saidclutching element, threaded bolts connected to said pressure member andextending rearwardly thereof parallelto the direction that said pressuremember is shiftable, manually controlled means cooperating with saidbolts for shifting said pressure member, a follower member through whichsaid bolts extend, springs coiled around said bolts between saidfollower member and said pressure member, link motions connected to saidfollower member, and centrifugal weights rearwardly of said followermember and connected to said link motions, said weights through theagency of said link motions being adapted to automatically shift saidpressure member, saidbolts being adjustable in the direction in whichthe pressure member is shiftable for determining the shifting range ofthe clutching element substantially as and for the purpose described. s.In a clutch, driving and driven elements, a clutching member actuatablcto establish a driving connection between said driving and driven jelements, a pressure plate to the rear of said 7 clutching member andaxially movable for actuating said member to establish such drivingconnection, an. axially movable follower plate reanwardly of saidpressure plate and having cut-away sections therein, a yieldableconnection between said pressure plate'and said follower plate, aplurality of pivots rearwardly of said follower plate and movable withsaid driving element, centrifugal weights disposed on said pivots in amanner permitting of such weights swinging within said cut-awaysections, connecting means between said weights and said follower plate,said weights being automatically operable through said connecting meansto axially move said plates upon an increase in speed of the drivingelement, and manually operable means for shifting said pressure platewhen the weights are in an outward position, said means comprising aspring resisted manually operable device, means connected with saidpressure plate independently of .the automatic operating means, andactuating means between said manually shiftable device and the meansconnected with the pressure plate.

5. In a clutch, a driving shaft, a hollow flywheel rotatable with saiddriving shaft, a driven shaft extending through the rear side of saidflywheel, a clutch element movable axially onsaid driven shaft intooperative clutching engagement with said flywheel, apressure receivingmember shiftable; to effect such axial movement of the clutch element, afollower member having cut-away sections therein, yieldable connectingmeans interposed between said follower member and said pressurereceiving member. pivots on said flywheel to the rear of said followermember, centrifugal weights on said pivots andadapted to swing withinsaid cut-away sections, and connecting means between said weights andsaid follower member. said weights being operative through saidconnecting means to automatically shift said follower member and saidpressure re ceiving member coincidental with an increase in speed ofsaid flywheel.

6. In a clutch, driving and driven elements, an axially shiitableclutching element contributing .to a clutching connection between saiddriva follower plate cut-away sections therein, said bolts extendingthrough a part of such cutaway sections. springs about said bolts andoperative to maintain said plates in spaced relation. fulcrumsearried bythe driving element rearwardly 01- said plates, centrifugal weightspivotal about said iulcrums and movable in a part of said cut-awaysections, said weights having an operative connection with said followerplate for imparting axial movement thereto and to said pressure plateincident to'an increase in speed of said driving element. means on saidbolts for changing the spaced relationship oi said plates and hencethetorce normally exerted by said springs. and manually operable clutchactuating coupledwith said bolts.

a. aw,

